Fuel injected internal combustion engines are well known. In direct-injected engines, the injection tip of the fuel injector extends into the combustion chamber and includes a perforated plate, known in the art as a “spray director plate,” for dispersing and directing fuel injected from the injection valve. In a conventional engine fuel injection system, the injection tip of the injector extends into a plenum or rail of the engine's intake manifold where the injected fuel is mixed with intake air before being discharged into the engine's combustion chamber.
As is well known in the automotive arts, the configuration and positioning of a director plate with respect to the injection valve ball and valve seat are critical elements in the most fuel-efficient distribution of fuel into the manifold or firing chamber. A typical fuel injection valve includes a beveled circular seat and a reciprocably-actuated ball that seals against the seat in a circular sealing line.
The perforations through a director plate may be considered as fuel flow passages. It is known in prior art director plates to form a passage by drilling or punching with a tool from either the flow-entrance or flow-exit side, either parallel to or at an angle to the plate axis, resulting in a cylindrical passage having an abrupt corner at the tool entrance and typically a ragged or torn corner at the tool exit. A known problem in prior art fuel injectors is that, over time in use, deposits may build up at the flow entrances and exits to the cylindrical passages, as well as on the sidewalls, adversely affecting the control of the volume and spray pattern of fuel.
What is needed in the art is a fuel injector director plate having an improved configuration of flow passages that results in a reduced propensity to form deposits.
It is a principal object of the present invention to reduce the forming of deposits in the flow passages of a fuel injector spray director plate.